Wire Examples based on AVR ones of the same name

esp8266 · devyte · Feb 4, 2019 · Feb 4, 2019 · Feb 4, 2019 · Feb 4, 2019
commit c07687e47b37c90b0ed65bc1cbd5537498ac3748
diff --git a/libraries/Wire/examples/master_reader/master_reader.ino b/libraries/Wire/examples/master_reader/master_reader.ino
@@ -0,0 +1,37 @@
+// Wire Master Reader
+// by devyte
+// based on the example of the same name by Nicholas Zambetti <http://www.zambetti.com>
+
+// Demonstrates use of the Wire library
+// Reads data from an I2C/TWI slave device
+// Refer to the "Wire Slave Sender" example for use with this
+
+// This example code is in the public domain.
+
+
+#include <Wire.h>
+#include <PolledTimeout.h>
+
+#define SDA_PIN 4
+#define SCL_PIN 5
+const int16_t I2C_MASTER = 0x42;
+const int16_t I2C_SLAVE = 0x08;
+
+void setup() {
+  Serial.begin(115200);  // start serial for output
+  Wire.begin(SDA_PIN, SCL_PIN, I2C_MASTER);        // join i2c bus (address optional for master)
+}
+
+void loop() {
+  using periodic = esp8266::polledTimeout::periodic;
+  static periodic nextPing(1000);
+
+  if(nextPing) {
+    Wire.requestFrom(I2C_SLAVE, 6);    // request 6 bytes from slave device #8
+
+    while (Wire.available()) { // slave may send less than requested
+      char c = Wire.read(); // receive a byte as character
+      Serial.print(c);         // print the character
+    }
+  }
+}
diff --git a/libraries/Wire/examples/master_writer/master_writer.ino b/libraries/Wire/examples/master_writer/master_writer.ino
@@ -0,0 +1,38 @@
+// Wire Master Writer
+// by devyte
+// based on the example of the same name by Nicholas Zambetti <http://www.zambetti.com>
+
+// Demonstrates use of the Wire library
+// Writes data to an I2C/TWI slave device
+// Refer to the "Wire Slave Receiver" example for use with this
+
+// This example code is in the public domain.
+
+
+#include <Wire.h>
+#include <PolledTimeout.h>
+
+#define SDA_PIN 4
+#define SCL_PIN 5
+const int16_t I2C_MASTER = 0x42;
+const int16_t I2C_SLAVE = 0x08;
+
+void setup() {
+  Wire.begin(SDA_PIN, SCL_PIN, I2C_MASTER); // join i2c bus (address optional for master)
+}
+
+byte x = 0;
+
+void loop() {
+  using periodic = esp8266::polledTimeout::periodic;
+  static periodic nextPing(1000);
+
+  if(nextPing) {
+    Wire.beginTransmission(I2C_SLAVE); // transmit to device #8
+    Wire.write("x is ");        // sends five bytes
+    Wire.write(x);              // sends one byte
+    Wire.endTransmission();    // stop transmitting
+
+    x++;
+  }
+}
diff --git a/libraries/Wire/examples/slave_receiver/slave_receiver.ino b/libraries/Wire/examples/slave_receiver/slave_receiver.ino
@@ -0,0 +1,39 @@
+// Wire Slave Receiver
+// by devyte
+// based on the example by Nicholas Zambetti <http://www.zambetti.com>
+
+// Demonstrates use of the Wire library
+// Receives data as an I2C/TWI slave device
+// Refer to the "Wire Master Writer" example for use with this
+
+// This example code is in the public domain.
+
+
+#include <Wire.h>
+
+#define SDA_PIN 4
+#define SCL_PIN 5
+
+const int16_t I2C_MASTER = 0x42;
+const int16_t I2C_SLAVE = 0x08;
+
+void setup() {
+  Serial.begin(115200);           // start serial for output
+
+  Wire.begin(SDA_PIN, SCL_PIN, I2C_SLAVE); // new syntax: join i2c bus (address required for slave)
+  Wire.onReceive(receiveEvent); // register event
+}
+
+void loop() {
+}
+
+// function that executes whenever data is received from master
+// this function is registered as an event, see setup()
+void receiveEvent(size_t howMany) {
+  while (1 < Wire.available()) { // loop through all but the last
+    char c = Wire.read(); // receive byte as a character
+    Serial.print(c);         // print the character
+  }
+  int x = Wire.read();    // receive byte as an integer
+  Serial.println(x);         // print the integer
+}
diff --git a/libraries/Wire/examples/slave_sender/slave_sender.ino b/libraries/Wire/examples/slave_sender/slave_sender.ino
@@ -0,0 +1,32 @@
+// Wire Slave Sender
+// by devyte
+// based on the example of the same name by Nicholas Zambetti <http://www.zambetti.com>
+
+// Demonstrates use of the Wire library
+// Sends data as an I2C/TWI slave device
+// Refer to the "Wire Master Reader" example for use with this
+
+// This example code is in the public domain.
+
+
+#include <Wire.h>
+
+#define SDA_PIN 4
+#define SCL_PIN 5
+const int16_t I2C_MASTER = 0x42;
+const int16_t I2C_SLAVE = 0x08;
+
+void setup() {
+  Wire.begin(SDA_PIN, SCL_PIN, I2C_SLAVE);                // join i2c bus with address #8
+  Wire.onRequest(requestEvent); // register event
+}
+
+void loop() {
+}
+
+// function that executes whenever data is requested by master
+// this function is registered as an event, see setup()
+void requestEvent() {
+  Wire.write("hello\n"); // respond with message of 6 bytes
+  // as expected by master
+}